9-21974861-C-A

Position:

chr9-21974861-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 8P and 1B. PP5_Very_StrongBP4

The ENST00000498124.1(CDKN2A):c.-34G>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000603 in 1,509,400 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000066 ( 0 hom. )

Consequence

CDKN2A
ENST00000498124.1 5_prime_UTR

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:13O:1

Conservation

PhyloP100: -0.827

Variant links:

Genes affected

CDKN2A (HGNC:1787): (cyclin dependent kinase inhibitor 2A) This gene generates several transcript variants which differ in their first exons. At least three alternatively spliced variants encoding distinct proteins have been reported, two of which encode structurally related isoforms known to function as inhibitors of CDK4 kinase. The remaining transcript includes an alternate first exon located 20 Kb upstream of the remainder of the gene; this transcript contains an alternate open reading frame (ARF) that specifies a protein which is structurally unrelated to the products of the other variants. This ARF product functions as a stabilizer of the tumor suppressor protein p53 as it can interact with, and sequester, the E3 ubiquitin-protein ligase MDM2, a protein responsible for the degradation of p53. In spite of the structural and functional differences, the CDK inhibitor isoforms and the ARF product encoded by this gene, through the regulatory roles of CDK4 and p53 in cell cycle G1 progression, share a common functionality in cell cycle G1 control. This gene is frequently mutated or deleted in a wide variety of tumors, and is known to be an important tumor suppressor gene. [provided by RefSeq, Sep 2012]

CDKN2A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PP5

Variant 9-21974861-C-A is Pathogenic according to our data. Variant chr9-21974861-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 182414.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-21974861-C-A is described in Lovd as [Pathogenic].

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.72). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDKN2A	NM_058195.4 linkuse as main transcript	c.194-3653G>T		intron_variant		ENST00000579755.2	NP_478102.2
CDKN2A	NM_000077.5 linkuse as main transcript			upstream_gene_variant		ENST00000304494.10	NP_000068.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000579755.2 linkuse as main transcript	c.194-3653G>T		intron_variant		1	NM_058195.4	ENSP00000462950		Q8N726-1
CDKN2A	ENST00000304494.10 linkuse as main transcript			upstream_gene_variant		1	NM_000077.5	ENSP00000307101	P2	P42771-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000433

AC:

AN:

115386

Hom.:

AF XY:

0.0000474

AC XY:

AN XY:

63326

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000564

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000778

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000656

AC:

AN:

1357220

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

668658

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000175

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000748

Gnomad4 OTH exome

AF:

0.0000711

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:13Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 20, 2024	Describes a nucleotide substitution 34 base pairs upstream of the ATG translational start site of the CDKN2A gene that creates an aberrant ATG translation initiation codon; Published functional studies demonstrate a damaging effect: decreases translation from the wild-type ATG and results in a truncated protein that significantly affects reporter activity (PMID: 9916806, 20093296); Nucleotide substitution has no predicted effect on splicing and is not conserved across species; This variant is associated with the following publications: (PMID: 26557774, 26775776, 19523171, 16896043, 25780468, 9916806, 20093296, 26581427, 26681309, 26099287, 12072543, 26681312, 16397522, 16905682, 15146471, 28495237, 29263814, 28830827, 30067863, 30117292, 30113427, 31567591, 33077847, 32482799, 34598035, 17713569, 29922827) -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 05, 2019	The best available variant frequency is uninformative because it is below the disease allele frequency. Found in at least one patient with expected phenotype for this gene. Low nucleotide conservation. Assessment of experimental evidence suggests this variant results in abnormal protein function. Very strong co-segregation with disease, and data include affected and unaffected individuals from multiple families. -
Pathogenic, criteria provided, single submitter	clinical testing	Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden	Nov 03, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Dec 01, 2023	CDKN2A: PP1:Strong, PM2, PS3:Moderate, PS4:Moderate -

Melanoma-pancreatic cancer syndrome

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	May 03, 2017	- -

Hereditary cancer-predisposing syndrome

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 29, 2022	The c.-34G>T pathogenic mutation is located in the 5' untranslated region (5'UTR) of the CDKN2A gene. This mutation results from a G to T substitution 34 nucleotides upstream from the first translated codon. This sequence alteration creates a potential AUG initiation codon at base -35 and translation initiation from this novel start site predicts a truncated protein with no homology to wild type (Liu L et al. Nat. Genet. 1999 Jan;21:128-32). Functional studies demonstrate that the c.-34G>T mutation severely reduces the reporter activity in every cell type tested (Bisio A et al. Hum. Mol. Genet. 2010 Apr;19:1479-91). This alteration was identified in an individual with at least 3 primary melanoma diagnoses (Li C et al. Melanoma Res. 2020 06;30:247-251). In addition, this alteration has been reported in numerous families with melanoma, pancreatic cancer, and/or atypical nevi, and has been shown to segregate with disease (Liu L et al. Nat. Genet. 1999 Jan;21:128-32; Berwick M et al. Cancer Epidemiol. Biomarkers Prev. 2006 Aug;15:1520-5; Florell SR et al. J. Invest. Dermatol. 2008 Aug;128:2122-5; Larre Borges A et al. Br. J. Dermatol. 2009 Sep;161:536-41; Harland M et al. Hered. Cancer Clin. Pract. 2014 Nov;12:20; Bruno W et al. J. Am. Acad. Dermatol. 2016 Feb;74:325-32; Puig S et al. Genet. Med. 2016 Jul;18:727-36; Taylor NJ et al. J. Invest. Dermatol. 2017 12;137(12):2606-2612; Brand R et al. Cancer. 2018 Sep;124(17):3520-3527). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 21, 2023	The CDKN2A locus encodes two different gene products, p16INK4a and p14ARF (https://www.ncbi.nlm.nih.gov/books/NBK7030/). This variant is located in the 5' untranslated region of the CDKN2A gene (P16INK4A). A functional study has shown that this variant creates a new translation initiation AUG codon, and translation initiation from this novel site results in a truncated protein, while blocking wild-type protein expression (PMID: 9916806). This variant has been reported in over thirty individuals affected with melanoma (PMID: 9916806, 16397522, 17713569, 18025365, 19523171, 25023876, 25780468, 26581427, 26681309, 26775776, 29263814, 31567591) and has been shown to segregate with melanoma and pancreatic cancer in four different families (PMID: 9916806). This variant has been identified in 6/146754 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Pathogenic. -

Melanoma and neural system tumor syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Jan 31, 2024

- -

Melanoma;C0919267:Ovarian neoplasm

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Oct 14, 2021

ACMG classification criteria: PS3 supporting, PS4 strong, PM2 moderate, PP1 strong -

CDKN2A-related disorder

Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Sep 17, 2024

The CDKN2A c.-34G>T variant is located in the 5' untranslated region. This variant corresponds to a deep intronic position in the alternate transcript for this gene that encodes p14ARF (NM_058195.3:c.194-3653G>T). This variant has been reported in individuals with melanoma and segregated within families (Liu et al. 1999. PubMed ID: 9916806; Harland et al. 2000. PubMed ID: 10738302; Andreotti et al. 2016. PubMed ID: 26581427). It has also been reported in an individual with pancreatic adenocarcinoma (Brand et al. 2018. PubMed ID: 30067863). In vitro experimental studies indicate that this variant results in a novel alternative initiator that subsequently leads to decreased translation from the normal start site and ultimately a truncated protein (Liu et al. 1999. PubMed ID: 9916806). In addition, this variant significantly alters transcriptional activity as observed by in vitro reporter assay (Bisio et al. 2010. PubMed ID: 20093296). This variant is reported in 6 of ~147,000 alleles in gnomAD; however, the data quality is questionable and should be interpreted with caution. This variant is interpreted as pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/182414/). This variant is interpreted as pathogenic. -

Melanoma and neural system tumor syndrome;C1835044:Melanoma, cutaneous malignant, susceptibility to, 2;C1838547:Melanoma-pancreatic cancer syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Familial melanoma

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 20, 2024

This variant occurs in a non-coding region of the CDKN2A (p16INK4a) gene. It does not change the encoded amino acid sequence of the CDKN2A (p16INK4a) protein. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has been observed in individual(s) with familial melanoma (PMID: 9916806, 10738302, 16397522, 17713569, 18025365, 18337833, 19523171). It is commonly reported in individuals of British ancestry (PMID: 9916806, 10738302, 16397522, 17713569, 18025365, 18337833, 19523171). ClinVar contains an entry for this variant (Variation ID: 182414). Studies have shown that this variant alters CDKN2A (p16INK4a) gene expression (PMID: 9916806, 20093296). For these reasons, this variant has been classified as Pathogenic. -

Melanoma, cutaneous malignant, susceptibility to, 2

Other:1

risk factor, no assertion criteria provided

literature only

OMIM

Jan 01, 1999

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.72

CADD

Benign

2.5

DANN

Benign

0.63

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over